1. Field of the Invention
This invention is related to the field of fastening devices preferably for securing a wheel to a vehicle and, more particularly, to a composite nut and decorative cap for fastening a wheel to a threaded stud of a vehicle hub.
2. Description of the Related Art
In the development of functional hub caps and wheel fasteners for vehicles, a decorative art has emerged. Wheel covers of various shapes designs, and compositions (alloys) are now readily available and are popular options on various vehicles to accentuate appearance.
In addition to distinctive wheel covers, decorative nut caps have been designed to complement the wheel covers. The nut caps cover the nuts which nuts are frequently called nut inserts. The nut and cap combination fasten the wheel to the threaded studs of a vehicle hub. In addition to a decorative effect, the nut caps protect the nut inserts from adverse effects of the weather, such as rusting, etc.
In the prior art fasteners, nut caps have been variously top welded (U.S. Pat. No. 4,123,961), crimped (U.S. Pat. No. 3,364,806) flange welded (U.S. Pat. No. 4,775,272) and glued onto the nut inserts such that the cap will provide the decorative and protective functions. The exterior sides of the nut cap are provided with wrenching surfaces referred to as wrench flats. A nut-rotating wrench is then applied to the wrench flats of the cap to rotate the combination nut cap and nut insert to tighten or loosen the wheel to the vehicle hub. The cap and nut insert rotate together to provide the desired mechanical function. Each of the foregoing patents is incorporated by reference.
Despite the many creative ways for fastening the nut insert and the nut cap together, the nut cap sometimes becomes separated from the nut insert. The tensile and shear strength of the adhesive may be too low and give way; salt and/or water may work between the nut cap and the nut and cause rusting which can cause separation of the nut cap and the nut insert in response to the stress of repetitive loosening or tightening the nut on the stud; and a small percentage of these fasteners may separate despite manufacturing precautions. Irrespective of the cause of the separation, its effect upon the user of the capped wheel nut is significant. Although the nut cap is designed to fit a standard size nut-rotating wrench, when the nut cap disengages from the nut insert, it is difficult, if not impossible to rotate the nut insert because the nut insert, which is positioned inside the cap, is "undersized", i.e., smaller than the standard nut-rotating wrench. This unexpected dilemma can be both frustrating and dangerous for a stranded vehicle operator who is unable to change a flat tire on the vehicle once a nut cap has been dislodged from the nut insert because the standard wrench does not properly engage the "undersized" nut insert.
It is an object of this invention to provide a simple but effective way of addressing the problem of providing a decorative and functional cap and wheel nut insert combination, yet in the case of the cap being separated from the wheel nut insert, to provide a suitable remedy for enabling rotation (and thus tightening or loosening) of the non-capped wheel nut insert.